Starting as early as next year, software developers will be able to design a single application that works with a touchscreen or mouse and trackpad depending on whether it's running on the iPhone and iPad operating system or on Mac hardware, according to people familiar with the matter.

Developers currently must design two different apps - one for iOS, the operating system of Apple's mobile devices, and one for macOS, the system that runs Macs. That's a lot more work. What's more, Apple customers have long complained that some Mac apps get short shrift. For example, while the iPhone and iPad Twitter app is regularly updated with the social network's latest features, the Mac version hasn't been refreshed recently and is widely considered substandard. With a single app for all machines, Mac, iPad and iPhone users will get new features and updates at the same time.

Apple currently plans to begin rolling out the change as part of next fall's major iOS and macOS updates, said the people, who requested anonymity to discuss an internal matter. The secret project, codenamed "Marzipan", is one of the tentpole additions for next year's Apple software road map. Theoretically, the plan could be announced as early as the summer at the company's annual developers conference if the late 2018 release plan remains on track. Apple's plans are still fluid, the people said, so the implementation could change or the project could still be canceled.

This is a massive change in Apple's direction. The company and its supporters have always held fast to the concept that there should be two distinct and different operating systems with two distinct and different user interfaces, very much the opposite of what Microsoft is still trying to do with Windows Metro applications and their Surface line-up. This change is basically a complete embrace of Microsoft's vision for the future of computing.

This will have tremendous consequences for both iOS and macOS. For iOS, it probably means we get more advanced, fuller-featured applications, and I think this also pretty much confirms we're going to see a mouse pointer and trackpad/mouse support on iOS in the very near future - just as I predicted earlier this year. For macOS, it might mean a broader base of applications to choose from, but also possibly a dumbing-down of existing applications. A number of Apple applications already work very much like the article states, and they certainly lost functionality on the macOS side of things.

On the more speculative side, this could be the next step in deprecating macOS, which is, in my unfounded opinion, still Apple's ultimate goal here. Note how Apple isn't bringing macOS applications to iOS, but vice versa. Make of that what you will, but I wouldn't have too much faith in the long term viability of macOS as a platform distinct and separate from iOS.